Treatment of copper or copper-nickel mattes.



UNTED STATES PATENT QFFTGE.

JAMES TAYLOR, CARRICK, OF JOI-IANNESBURG, TEANS'V'AAL, ASSIGNOR 0F ONE-HALF TO BASIL STUART PATTISON, 0F JOHANNESBURG, TBANSVAAL.

TREATMENT OF COPPER OR COPPER-NICKEL MATTES.

seas i7.

N0 Drawing. Original application filed February 18, 1908, Serial No. 416,616.

filed October 6, 1908.

T 0 all whom it may concern:

Be it known that l, JAlvIES TAYLOR OAR- iziok, geologist, subject of the King of Great Britain, residing at the New Club, J ohannesburg, Transvaal, have invented new and use ful improvements in the Treatment of Copper or Copper-Nickel Mattes, of which the following is a specification.

The present invention relates to the treatment of copper and copper nickel mattes for the r covcry of the valuable metallic constituents thereof: this application being a division from application Serial No. 416,616, filed February 18th, 1908.

Matte for treatment according to the present invention is preferably of low grade, or in other words largely diluted with ferrous sulfid, in order that it may be readily soluble in dilute sulfuric acid as hereafter mentioned, and also to avoid the expense of producing high grade matte, which while often being economically essential in other processes, is in the present instance unnecessary.

In carrying out the invention the matte is first digested in acid, and "the sulfureted hydrogen gas thereby evolved is collected in a suitable gas holder. Such gas is then burned, being in the preferred method of operation employed as fuel in subsequent steps of the invention, such as the fusion and mingling of high grade and low grade mattes or sulfids for the purpose of rendering them soluble, or in the bessemerizing of cuprous sulfid to be referred to later; or in other purposes connected with the treatment works, such as the raising of steam. The product of the combustion of the sulfureted hydrogen viz. sulfur dioXid gas, is then converted into sulfuric acid by well known means, and such acid is employed for the digestion of further quantities of matte.

The digester contents consist of an acid solution of ferrous sulfate, and sulfates of nickel and cobalt when these metals were originally present in the ore, together with a residue of cuprous sullid containing usually some nickel sulfid.

The solid residue is collected, as by filter pressing; and treated by bessemerizing. The product being, except for its nickel contents and small quantities of such impurities as arsenic, chemically pure sulfid and containing very little iron or excess silica, is pecul- Specification of Letters Patent.

Patented Nov. 9, 1909.

Divided and this application Serial No. 456,434.

iarly adapted to bessemerizing in an economical manner; one grave drawback of such process as usually carried out, viz. the presence of large quantities of base-forming ferruginous material which is liable to cause excessive corrosion of the converter lining, being in this case absent. Such ferruginous material however constitutes an essential part of the fuel in the known copper con verting process, and is therefore replaced in the present case by extraneous fuel, for which purpose any suitable gaseous or liquid fuel capable of being blown into the converter may be employed. Preferably, however, the whole or a portion of the sulfureted hydrogen produced by the digestion of the matte is employed as fuel in the converter, for which purpose it is eminently suitable owing to its high calorific value and the absence of objectionable combustion products. Said gas may also be used to advantage to melt the cuprous sulfid previous to its conversion, when such fusion is not effected in the converter itself; and the resulting sulfur dioXid gas emitted by the converter and the melting furnace would be collected and conveyed to the acid plant as already mentioned.

In the case of nickeliferous ores, the cuprous sulfid from the digester carries a certain proportion of nickel, whichhas remained undissolved by the acid. Such nickel is recovered by providing in the converter just sutlicient silicious matter to form a concentrated nickeliferous slag, which may subsequently be treated in any desirable manner, as e. g. by being added to a subsequent charge in the original matte producing furnace. Any copper which may be slagged off with the nickel as silicate is thus recovered in the matte.

The digester liquor may be treated for the recovery of its valuable contents; and in particular, such copper as may have entered into solution is precipitated as sulfid and bessemerized, forexample, along with the original cupriferous residue.

A modified form of the invention may be employed with beneficial results in cases where it is undesirable to bessemerize the copper with extraneous fuel. Thus where a copper matte is of such low grade that in the ordinary course it would require re-smelting before it could be economically converted, a certain proportion of it may according to this invention, be digested for the production of cuprous sulfid. This product is then mixed with the remainder of the matte and the mixture bessemer'ized in the ordinary manner, the constituents being so proportioned as to raise the grade to the most advantageous degree for this purpose. By this method a second or concentrating smelt is avoided and with it the unnecessary production of slag and loss of copper therein; the recovery of nickel is facilitated; and a certain proportion of the iron and sulfur in the matte may if desired, be recovered as byproducts.

lVhat I claim and desire to secure by Letters Patent is:

1. The process which consists in digesting matte in acid, recovering substantially pure cuprous sulfid, and bessemerizing such cuprous sulfid with the use of extraneous gase- ..0us or Vaporous fuel.

2. The hereindescribed process which conslsts 1n producing sulfureted hydrogen and substantially pure eupr'ous sulfid, bes'semerizing the cuprous sulfid, and utilizing the sulfureted hydrogen as fuel in the bessemerizing process.-

3. The hereindescribed process which consists in producing sulfureted hydrogen and substantially pure cuprous sulfid, fusing the cuprous sulfid, bessemerizing the cuprous sulfid and utilizing the sulfureted hydrogen as fuel in the bessemerizing process.

41 The hereindescribed process of treating nickeliferous matte which consists in digesting the matte, bessemerizing the residual cuprous sulfid, and separating the nickel contained in the cuprous sulfid by slagging it off as nickel silicate.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

JAMES TAYLOR OARRICK.

Vitne'ss'es V J. lVILsoN, VVnsLEY E. JOHN. 

